diff --git a/inc/medleyfp.h b/inc/medleyfp.h
index e2d162f..295e912 100644
--- a/inc/medleyfp.h
+++ b/inc/medleyfp.h
@@ -27,7 +27,8 @@
     --------------------------------------------------  */
 
 #ifdef FLTINT
-volatile extern int  FP_error;
+#include <signal.h>
+extern volatile sig_atomic_t FP_error;
 
 /*  Note that a compiler may very likely move code around the arithmetic
     operation, causing this test (set by an interrupt handler) to be
diff --git a/src/timer.c b/src/timer.c
index d1bdd5a..2592f51 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -644,7 +644,7 @@ void int_unblock() {
 /************************************************************************/
 
 /* The global used to signal floating-point errors */
-volatile int FP_error = 0;
+volatile sig_atomic_t FP_error = 0;
 
 void int_fp_service(int sig, siginfo_t *info, void *context)
 {